Fixing PHP notice caused by WordPress 3.9 update.

Since WordPress 3.9, $wpdb::prepare requires at least one placeholder. The current line of code causes the following error:

>PHP Notice:  wpdb::prepare was called <strong>incorrectly</strong>. The query argument of wpdb::prepare() must have a placeholder. Please see <a href="http://codex.wordpress.org/Debugging_in_WordPress">Debugging in WordPress</a> for more information. (This message was added in version 3.9.) in /var/www/html/wp-includes/functions.php on line 3245

This is an error that will only effect multisite installs.

This pull fixes the notice, which appears hundreds of times per page load, causing a massive debug.log. Since we are not taking any input, we don't really need to prepare the query anyways.